Generally, a six-folded umbrella is an umbrella having six ribs to assemble the frame that obtains a small volume for facilitating carrying by users. As shown in FIG. 1, each of the conventional umbrella frames (1) includes a first rib (11), a second rib (12), a third rib (13), a fourth rib (14), a fifth rib (15), and a tail rib (16). It is known that the first rib (11), the second rib (12), the third rib (13), and the fourth rib (14) are usually formed to have a U-shaped cross-section and the ribs are pivoted with each other. When the conventional umbrella is closed as shown in FIG. 2, the ribs will be resistant against others and make the frame (1) be slightly expanded. Accordingly, the six-folded umbrella has a short length but has a large diameter. The volume of the collapsible umbrella in closed state is still large and it is not very convenient for carrying.